This was a world’s first example of a synchronised dual-screen film. Durex invited its viewers to peek ‘Behind Closed Doors’ with the aid of their app. When the commercial was played the audio triggered the app film to sync with it.

Durex ‘Behind Closed Doors’ – Audio Mix Case Study

TV Mix:

In order for it to launch promptly when the TV commercial was played, the app software needed to be able to clearly recognise the TV sound mix as a unique piece of audio with it’s own digital signature – using the built-in microphone of the phone or tablet device. This software responds best when the audio contains a broad range of frequencies across the entire listening spectrum, so to achieve this, various elements of specific frequencies had to be added.

The original piece of music contained many frequencies in the lower end of the spectrum as well as some high frequencies but less so across the mid-range. So we needed to build up the soundtrack to include elements that would fill this space.

For this, we experimented with adding layers of guitar and keyboard into the music track, which would not only fill the gaps required by the software but also compliment the track from a creative point of view. This improved the reaction time of the software and it’s ability to launch the app but it still needed to be more effective.

After further experimentation, we discovered that ‘spikey’ elements such as tambourines, shakers and snare drums worked really well so various percussive patterns were then added.

After mixing and then mastering the final music track, which had the effect of compressing all of these elements together, as well as adding some subtle atmospheric sound effects, the desired reaction time of the app was achieved, even at considerably low volume levels.

App Mix:

Due the predicted uncontrolled environments of people listening to the app sound mix in different rooms and at various proximities from the TV, it was decided that it would be unsuitable to have the music track played during the app mix at the same time as the TV mix. This is in case of any slight delay that may occur when listening to both mixes at the same time, where they could potentially clash and cause an unwanted ‘bad DJ’ effect!

It was decided that the app mix would have it’s own separate audio mix with corresponding sound effects that would compliment the TV mix when both were heard at the same time.